Safety automatic door stop



Aug. 21, 1956 J. J. REID ETAL SAFETY AUTOMATIC DOOR STOP Filed March 23, 1953 MES as own BY. I

INVENTOR. JAMES J. REID T ORNEYS United States Patent SAFETY AUTOMATIC DOORSTOP James lReid andJames F. Brown, Philadlphia, Pa.

Application March 23, 1953, Serial No. 344,258

ltl Claims. (0. 20 16) (Granted under Title 35,U."S. Cde:(1952), sec. '266) The invention described herein may be manufactured andusedby or forthe Governmentof the United States of America for governmental purposes without thepayment'of any royalties thereon or therefor.

The present invention-relatesto a latching device-or the like and more-particularly to a novel and improved automatic safety latch device which is simple in construetion and reliable in use.

The invention is primarily intendedfor us'e with the large type of pull-up doors which are oftentimes used to close relatively la'rge entrances o'fbuildings such'as vehicle entrances and the like. Thes'elarg'e doorsusu'ally also containone or more smallerdoorsthrough which personnel mayconveniently pass. Although the s'rnall doors are ordinarily provided with a conventional "type of door latch, the same frequently become unlatehed while the large door is 'in its raised op'en p'os'ition. In doing so they are 'then capableof swinging downwardly on their hinges with considerable force-thereby endangering the safety of persons working :anh/ or passing therebelow.

The principal object of-the present invention is toi provide a noveland'improveddevice for-automaticallylocking the smaller door in its closed condition as 'soo'n as the largerdoor'begins to move upwardlytowards its elevated overhead position.

'Other objects f and many of I the attendant advantages of this invention will be readily appreciated :as the 's'a'rne becomes better understood by reference to ithe following detailed descriptionwhen consideredin connection with the accompanying drawings wherein:

Figure 1 is a front 'elevational view 'of a large pullup type of door having asmallerpersonn'el 'd'oora'positioned therein and the improved safety latch of the present inventionmounted thereon;

Figure 2 is an enlarged view of one embodiment of the/improved safety latch shown in Figure 1;and

'Figure 3 isan'cnlarged view'of a modifiedembodiment of the safety-latch'shown in Figu're 1.

In general, the improved device for latching 'th'e i-small door in a large overhead type doorin' itsclosedposition includes aifirst member which is positionedon the large door and which is adapted "to "retractablymxtend downwardly beyond the lower extremity thereofi a second member 'Whichis also positioned on the "large doorand which is adapted to retractably extend upwardly beyond thelower'extremity of the small door; and=meansoperatively connected to the 'first'and'the secondmembers for simultaneously'moving the same between their'extended and retracted positions. Ithas'be'en'found that such a device though relativelysimple in-construction provides a reliable and effective safety latch.

One preferred embodiment of the present inve'ntionis shown in Figures 1 and 2 of the drawing. Asvillustrated therein, the enlarged vehicle entrance 'or the like Im the building 3 is provided with'a conventional ovei head type door lwhich as is 'cus'tomaryiin the art'isipreferably divided into thehorizontally 'hinged sections ld and 2,759,227 :P aten-ted -A-u g. 21, 1956 4b. Although the particular arrangement whereby the door 4 is operated between its-open and closed positions could take a variety of different forms, a full description of the same is not-considered expedient herein since it forms no'part of 'the present invention. It need merely be understood .for a complete understanding of the pres- 'e'rlt invention that the door 4 moves in any suitable manner from a closed position (where its bottom edge'4c engages the floor'ofthe building) upwardly and-then inwardly toward its overhead or elevated open position.

As shown'in Figure l of the drawing, the small door or the like 5 which is hinged at '6 and 7 to the large door 4 in any suitable manner'is preferably spaced at small distance from the bottom edge 40 of the large door 4. This provides'the conVentionakstep-over portion of the'large door which is generally designated in the drawing by the referencenumeral 8 and upon which the improved latching mechanism of the present inveritionis preferably mounted.

Accordingly, "the channel-shaped housing or casing9 is secured tothe step-overportidn ofthe largedoorin any suitable manner such as by cap screws or the like. The lever or=the like ll} which is disposed within the housing 9 is pivotally secured thereto preferably by'means of the pin member or the like '11. or the like l'ft which is pivotally secured to one extremity er the lever l'ii-preferably'by means'of the slot lfiformed therein an'd'the pin member '14 extends downwardly therefrom through the conventional guide or bracket 15 which is secured in any suitable manner to the'inner surface of the housing 9. lu this'way as will bemore apparent"hereinafter th'e arm 12 is adapted to slide in a verticalimanne'r within the bracke't 15 'whereby (depending "upon the angular dis'pbition of "the pivoted lever in the'lowerextremity of the arm assumes either an extended or a retracted position with respect to the bottom edge of the large door 4.

The arm or the like E6 which ispre'fer'ably similarly pivotally secured 'to the opposite extremity Of the lever 10 by means :of the slot 17 and =thepin'member 18 extends upwardly therefrom through 'the guide or bracket member 19 which is-secured to'the casing 9-in anysuitable manner. As=will also be'more apparenthereinafter depending upon the angular disposition of the lever 10 the arm -16 assumes-either an extended or a retracted position with respect to the dipper edge of the stepover portion of the large-door. Any suitable device such as the elongated tension spring or the like 20 which'is preferably secured as shown between the bracket 15 and an upperportion of :the arm -12 biases the lever 10 in a clockwise fashion toward --a position where both of the arms 12 and 16 normally occupy theirextended positions.

In operation the improved latching device which is constructed in accordance with the present invention automatically moves between its latched and its onlatched conditions depending upon the position -of the large door 4. Accordingly, when the large-door 4-occupies its lowermost and closed position, the floor of the building 3 engages the lower extremity of the arm 12 and urges it upwardly'against the bias of the spring 20. This causes the lever :10 to rotate about its pivot in a counterclockwise direc'tionand consequently also-moves the arm 16 -to its retracted position. In this condition the small door 5 is unlatched and may be opened and closed as desired. When, however, the'largedoor begins to-open andmovetowards itsoverhead or 'el'evated position, the spring'Zll immcdiately'urges'th'e arm 12 downwardly thereby-causing the :lever 19 to rotate in "a clockwise direction and to move the arm 16 upwardly into latching engage'rnent with the bottornsportion of the small The arm door 5. In this way the small door is positively and securely latched in its closed position while the large door is open and the safety of persons working and/or passing therebelow is better assured.

A modified embodiment of the present invention is illustrated in Figure 3 of the drawing. As shown therein, the operative connection between the extendable and retractible arms or the like 31 and 32 includes the complementary toothed rack portions 31:: and 32a thereof and the pinion 33 with which the rack portions cooperate. As in the previously described embodiment of the in vention one or more tension springs or the like 34 normally bias the arms toward their extended positions.

Although both embodiments of the improved latching mechanism of the present invention have been shown and described herein as being mounted on and housed in a suitable casing which is secured to the step-over portion of the large door, it is to be understood that the same could instead be positioned within a suitably hollowed portion of the door without departing from the spirit or scope of the present invention.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In combination with a large overhead type of door having a small door disposed therein a device for latching the said small door in its closed condition comprising a first member which is slidably positioned on the large door and which is adapted to retractably extend downwardly beyond the lower extremity thereof; a second member which is also slidably positioned on the large door and which is adapted to retractably extend beyond the jamb of the small door; and means operatively conected to the said first and second members for simultaneously moving them between their extended and retracted positions.

2. In combination with a large overhead type of door having a small door disposed therein a device for latching the said small door in its closed condition comprising a housing mounted on a step-over portion of the large door, the step-over portion being disposed between juxtaposed bottom edges of the said large door and the said small door; a first member which is slidably positioned in the housing and which is adapted to retractably extend downwardly through an opening in the housing and beyond the lower extremity of the large door; a second member which is also slidably positioned in the housing and which is adapted to retractably extend upwardly beyond the lower extremity of the small door; and means operatively connected to the said first and second members for simultaneously moving them between their ex tended and retracted positions.

3. In combination with a large overhead type of door having a small door disposed therein a device for latching the said small door in its closed condition comprising a first member which is slidably positioned on the large door and which is adapted to retractably extend downwardly beyond the lower extremity thereof; a second member which is also slidably positioned on the large door and which is adapted to retractably extend beyond the jamb of the small door; means operatively connected to the said first and second members for simultaneously moving them between their extended and retracted positions; and means for normally biasing the said first and second members toward their extended positions.

4. In combination with a large overhead type of door having a small door disposed therein a device for latching the said small door in its closed condition comprising a lever which is pivotally positioned on a step-over portion of the large door, the step-over portion being disposed between juxtaposed bottom edges of the said large door and the said small door; a first member which is pivotally connected to one extremity of the lever and which is adapted to retractably extend downwardly beyond the bottom edge of the large door; a second member which is pivotally connected to the opposite extremity of the lever and which is adapted to retractably extend upwardly beyond the bottom edge of the small door; and means for normally biasing the said first and second members toward their extended positions.

5. In combination with a large overhead type of door having a small door disposed therein a device for latching the said small door in its closed condition comprising a lever which is pivotally positioned on a step-over portion of the large door, the step-over portion being disposed between juxtaposed bottom edges of the said large door and the said small door; a first member which is pivotally connected to one extremity of the lever and which is adapted to retractably extend downwardly beyond the bottom edge of the large door; a second member which is pivotally connected to the opposite extremity of the lever and which is adapted to retractably extend upwardly beyond the bottom edge of the small door; and a tension spring which is secured to and extends between the bottom of the large door and an upper portion of the said first member and which normally urges the said first and second members toward their extended positions.

6. In combination with a large overhead type of door having a small door disposed therein a device for latching the said small door in its closed condition comprising a lever which is pivotally positioned on a step-over portion of the large door, the step-over portion being disposed between juxtaposed bottom edges of the said large door and the said small door; a bracket member mounted on the step-over portion of the large door; a first arm which is pivotally connected to one extremity of the lever and which is adapted to retractably extend downwardly through the bracket member and beyond the bottom edge of the large door; another bracket member mounted on the step-over portion of the large door; a second arm which is pivotally connected to the opposite extremity of the lever and which is adapted to retractably extend upwardly through the said other bracket member and beyond the bottom edge of the small door; and means for normally biasing the said first and second arms toward their extended positions.

7. In combination with a large overhead type of door having a small door disposed therein a device for latching the said small door in its closed condition comprising a pinion which is pivotally positioned on a step-over portion of the large door, the step-over portion being disposed between juxtaposed bottom edges of the said large door and the said small door; a first rack member which is operatively connected to the pinion and which is adapted to retractably extend downwardly beyond the bottom edge of the large door; a second rack member which is also operatively connected to the pinion and which is adapted to retractably extend upwardly beyond the bottom edge of the small door; and means for normally biasing the said first and second rack members toward their extended positions.

8. In combination with a large overhead type of door having a small door disposed therein a device for latching the said small door in its closed condition comprising a pinion which is pivotally positioned on a step-over portion of the large door, the step-over portion being disposed between juxtaposed bottom edges of the said large door and the said small door; a first rack member which is operatively connected to the pinion and which is adapted to retractably extend downwardly beyond the bottom edge of the large door; a second rack member which is also operatively connected to the pinion and which is adapted to retractably extend upwardly beyond the bottom edge of the small door; and a tension spring which is secured to and extends between the bottom of the large door and an upper portion of the said first rack member and which normally urges the said first and second rack members toward their extended positions.

9. In combination with a large overhead type of door having a small door disposed therein a device for latching the said small door in its closed condition comprising a pinion which is pivotally positioned on a step-over portion of the large door, the step-over portion being disposed between juxtaposed bottom edges of the said large door and the said small door; a bracket mounted on the step-over portion of the large door; a first rack member which is operatively connected to the pinion and which is adapted to retractably extend downwardly through the bracket and beyond the bottom edge of the large door; another bracket mounted on the step-over portion of the large door; a second rack member which is operatively connected to the pinion and which is adapted to retractably extend upwardly through the said other bracket and beyond the bottom edge of the small door; and means for normally biasing the said first and second rack members toward their extended positions.

10. In combination with a large overhead type of door having a small door disposed therein a device for latching the said small door in its closed condition comprising a housing mounted on a step-over portion of the large door, the step-over portion being disposed between juxtaposed bottom edges of the said large door and the said small door; a first member which is slidably positioned in the housing and which is adapted to retractably extend downwardly through an opening in the housing and beyond the lower extremity of the large door; a second member which is also slidably positioned in the housing and which is adapted to retractably extend upwardly beyond the lower extremity of the small door; means operatively connected to the said first and second members for simultaneously moving them between their extended and retracted positions; and means for normally biasing the said first and second members toward their extended positions.

References Cited in the file of this patent UNITED STATES PATENTS 190,341 Lambkin May 1, 1877 359,183 Sherwood Mar. 8, 1887 788,515 Carlson May 2, 1905 2,017,012 Morgan Oct. 8, 1935 2,461,284 Kemmet Feb. 8, 1949 

